CALGARY, Alberta, Nov 15 (Reuters) - Canadian oil and gas producer Obsidian Energy, formerly known as Penn West Petroleum Ltd, said on Wednesday it would pay $8.5 million to resolve a lawsuit by U.S. securities regulators accusing it of accounting fraud.

Calgary-based Obsidian Energy said in a statement it agreed to pay the financial penalty without admitting or denying any of allegations contained in a lawsuit the U.S. Securities and Exchange Commission filed Manhattan federal court in June.

The SEC alleged that from 2012 to 2014, Penn West and the executives executed a scheme to deceive investors about its financial condition by understating operating expenses and related metrics.

The SEC said Penn West artificially reduced its operating costs by as much as 20 percent and improved metrics for oil extraction efficiency by moving hundreds of millions of dollars from operating expense accounts to capital expenditure accounts.

The company issued a statement at the time saying the lawsuit was based on historic accounting practices that were discovered and reported to the SEC in July 2014.

"Our settlement resolves this legacy Penn West issue, and we are focused on looking forward as a new company," David French, chief executive of Obsidian Energy, said on Wednesday in a statement.

The settlement is subject to court approval.

Penn West was one of Canada's largest oil and gas producers at the time of the alleged offences, producing around 100,000 barrels of oil equivalent per day.

It has since downsized by selling most of its assets and now produces 31,000 boepd, primarily in Alberta's Cardium, Peace River and Viking plays.

"We view the settlement positively, given the very limited financial impact," GMP FirstEnergy analyst Darren Engels said in a research note. "The settlement with the SEC enables the company to move forward away from the historical issue and remain focused on operations."

The SEC is continuing to pursue claims against former Chief Financial Officer Todd Takeyasu and former Vice President of Accounting and Reporting Jeffery Curran, both of whom have filed motions to dismiss the case.

Former Operations Controller Waldemar Grab, who was also named as a defendant in the lawsuit, previously agreed to a settlement with the SEC.

The case is U.S. Securities and Exchange v. Penn West Petroleum Ltd, et al, U.S. District Court, Southern District of New York, No. 17-cv-04866. (Reporting by Nia Williams in Calgary; additional reporting by Nate Raymond in Boston; Editing by Alistair Bell and Richard Chang)